1. Field of the Invention
The present invention relates to a foldable sound attenuator, especially to a sound attenuator allowing a plurality of sound absorbing plates to be folded and stored in a case by utilizing at least a folding plate and at least a hinge so as to reduce the volume.
2. Description of Related Art
For the equipment in a machine room, when noise and heat are generated, an operation of ventilating and heat dissipating has to be processed, so at least an open hole is require to be formed on a wall of the machine room; as such, a sound attenuator (or sound attenuating equipment) has to be installed in the open hole for reducing the outgoing sound. When the sound attenuator (or the sound attenuating equipment) is installed, because the occupied space is rather large, when the required amount of heat to be dissipated is a lot, the dimension of the open hole has to be correspondingly enlarged, and this often result in there may not be enough space for forming the open hole and installing the sound attenuator, thereby causing the whole heat dissipating and soundproof effect to be poor.
In addition, when an iron rolling door installed in the machine room is closed, the performance of reducing noise volume is not as sufficient as the cement wall (the iron rolling door can reduce about 10˜15 dB of noise, and the cement wall can reduce about 50 dB of noise), so noise would be transferred out to the exterior through the iron rolling door and an effective sound attenuating effect cannot be provided.
Moreover, when the amount of open holes in the interior is not enough, the iron rolling door would be opened for being served as a ventilation hole, thus noise would be transferred out to the exterior without being attenuated at all.
Referring to FIG. 1a and FIG. 1b, wherein FIG. 1a is a schematic view illustrating a conventional sound attenuator; and FIG. 1b is another schematic view illustrating the conventional sound attenuator. As shown in figures, a conventional sound attenuator 100 includes a case 110 and a plurality of sound attenuating plates 120. The plural sound attenuating plates 120 are respectively disposed in the case 110, and two sides of each of the sound attenuating plates 120 are respectively formed with a plurality of punch holes 121, the interior of the sound attenuating plate 120 is filled with a sound absorbing material (not shown in figures), the sound absorbing material is e.g. but not limited to sound absorbing cottons for achieving a sound attenuating effect.
Referring to FIG. 2, which is a schematic view illustrating the installation of a conventional sound attenuator. As shown in FIG. 2, the above-mentioned conventional sound attenuator often requires an air inlet 130 and an air outlet 140 to be formed on the wall of the machine room for the purpose of ventilation, the area of the air inlet 130 and that of the air outlet 140 are determined by the required ventilating level, and because noise would be transferred out to the exterior through the air inlet 130 and the air outlet 140, the sound attenuator 100 is required to be respectively installed therein for preventing the outgoing noise; however, the installed sound attenuator 100 is heavy and large, so only a fastening means can be adopted for the installation and a large space is therefore occupied.
In view of the above-mentioned disadvantages, the present invention provides a foldable sound attenuator for improvements.